Sound Thinking
Law Enforcement
ANNOUNCEMENT:
ShotSpotter changes corporate name to SoundThinking and launches SafetySmart Platform for safer neighborhoods

7,599,252: Acoustic location of gunshots using combined angle of arrival and time of arrival measure

Type:

US

Application Number:

12/172163

Publication Date:

20091006

Filing Date:

20080711

Abstract:

A gunshot location system computes candidate gunshot locations [314] from angle-of-arrival information [304, 308] and time-of-arrival information [312] provided by acoustic sensors [300, 302]. In addition to an angle, each sensor calculates an angular uncertainty [306, 310] from impulses received at four or more microphones having rotational symmetry. An intersection of one or more time-of-arrival hyperbolas with one or more angle-of-arrival beams [322] is used to determine a candidate gunshot location. In simple environments, a location can be confirmed with just two sensors allowing sensor density to be significantly reduced, while in complex environments including reflections, blocking, and interfering acoustic events, the additional angle-of-arrival information improves location accuracy and confidence, allowing elimination of candidate locations inconsistent with the combined time-of-arrival and angle-of-arrival information.

More Information:

Search